It’s fifty years since Philadelphia, Here I Come! premièred at the Dublin Theatre Festival, establishing Brian Friel’s international reputation. This new Lyric Theatre production is doubtless one of many that will be mounted globally to mark the play’s first half-century of existence. It does a solid job of delineating the emotional and psychological conflicts endured by Gar, the would-be emigrant, and of emphasising Philadelphia’s enduring relevance in an Ireland where thousands are once again sailing (or flying) far from native soil, seeking economic and material betterment in other places.

It’s the pain of those the emigrant leaves behind which comes over strongest in director Andrew Flynn’s staging. The thin-lipped stoicism of housekeeper Madge conceals, in Stella McCusker’s shrewdly circumspect performance, a well of anxiety and regretfulness just below the surface. The Master Boyle of Enda Gates is likewise haunted by a quiet desperation, while Susan Davey skilfully conveys the hurt and frustration experienced by Gar’s sweetheart Kate, when he fails to fight their corner with her father.

Capping all these cameos of broken dreams and thwarted aspirations, however, is Des McAleer’s absorbing portrayal of S.B. O’Donnell, the paterfamilias whom Gar rages against, and with whom he can make no meaningful connection. McAleer’s is a properly understated performance, but you can’t stop watching him: the merest twitch or grimace seems to bespeak an underlying, barely trammelled confusion and heartache. You feel S.B’s love for Gar, and sense the reasons why he is unable to express it; you also clearly see why he causes his son such painful disappointment and frustration. Conveying both things is difficult, but the nuanced minimalism of McAleer’s performance achieves it.

There is less nuance in the interchanges between the two actors playing Gar Public and Gar Private, Peter Coonan and Gavin Drea respectively. In the first half of the play particularly their dialogue pings along at a spanking velocity, but it’s all a little unremitting, more full of raw energy than it is of psychological subtlety, which Friel’s script possesses in generous quantities. Drea is particularly frenetic, more the bullying alter-ego of Freudian analysis than the sly, insinuating Mephistopheles of Faustian legend. Perhaps press-night adrenalin was a factor: it would be good if later in the run more light and shade could be factored into the Gar Public/Private relationship, and more elbow-room for the audience to inhabit and reflect upon the crucial issues and dilemmas the two characters are forever tossing back and forward to one another.

It’s odd too that more attention has not been paid to the question of accents, which have a crucial role to play in Philadelphia in clearly establishing a sense of place, and underpinning the social and intellectual distinctions between characters. Too often in this Lyric production they are simply confusing, each actor seemingly left to peddle his or her own generic take on Irish-English, with little sense of thought-through consistency or dramatic justification. It seems a small thing, but cumulatively it matters, blurring the sharply sculpted contours and poetic cadences of Friel’s writing.

Owen MacCárthaigh’s split-level set is simple in conception but effective, its upper layer framed as Gar’s sparsely furnished bedroom, while at floor level the back-parlour of the O’Donnell household is minimally accoutred, with plain wooden flooring and undecorated surfaces. Ciaran Bagnall lights both spaces effectively, evoking a certain gloominess of aspect without erring into unnecessarily dank or maudlin territory.

Andrew Flynn’s direction of crucial scenes is generally sure-footed, if short on moments of special revelation. The set-piece involving S.B. and Canon O’Byrne (an affable, chuckling Niall Cusack), where they pore over a game of draughts while Gar Public bemoans their apparent immunity to deeper sentiment, is particularly telling in dramatising the gulf in sensibility between the soon-departing son and his father.

And when S.B. fails to remember the rainy afternoon spent fishing with his son fifteen years previously – an episode recalled by Gar Public as something of an epiphany – Flynn ekes from the father’s prosaic, throwaway denial a moment of stark emotional emptiness, distilling the uncomfortable truth that no two human beings remember the past in an exactly similar fashion, and that building our views of the present on the past is a highly precarious, if necessary strategy.

There are, in the final analysis, not quite enough moments of illumination in this Philadelphia, Here I Come! to make it truly special, though it is consistently enjoyable. What lies beneath Gar’s urge to quit Ballybeg for good remains famously unclear to the young man himself at the play’s conclusion. Friel’s externalisation of his struggle by putting two Gars, Public and Private, on stage to represent the contending influences sparring for domination, should be uniquely insightful and challenging for the audience. It’s only fitfully so in this particular production.

Terry Blain is an arts journalist and cultural commentator, contributing regularly to BBC Music Magazine, Opera Britannia, Culture Northern Ireland and other publications.